1. Field of the Invention
The present invention furthermore relates to the use of the thermoplastic molding materials for the production of fibers, films and moldings and to the fibers, films and moldings produced therefrom.
Owing to its crystallinity, syndiotactic polystyrene has a very high melting point of about 270.degree. C., high rigidity and tensile strength, dimensional stability, a low dielectric constant and high resistance to chemicals. The mechanical property profile is retained even at temperatures above the glass transition temperature. The preparation of syndiotactic polystyrene in the presence of metallocene catalyst systems is known and is described in detail, for example, in EP-A 0 535 582.
Owing to the remaining amorphous fraction in the syndiotactic polystyrene, the glass transition temperature is only about 100.degree. C.
2. Description of the Related Art
EP-A 0 732 359 and WO 95/34586 describe thermoplastic molding materials comprising copolymers of vinylaromatic monomers and 1,1-diphenylethylene and further polymers, such as polyphenylene ether or transparent high impact polystyrene having glass transition temperatures above 130.degree. C. However, these molding materials do not reach the high heat distortion resistance of molding materials which contain syndiotactic polystyrene and, in the case of blends with polyphenylene ether, tend to yellow.